Mix orange juice, lime juice, brown sugar, spices, salt and pepper. Mix with the prawns in a sealable container and marinate overnight.
Remove the prawns from the marinade. Put them onto skewers alternating with the pineapple chunks.
Barbecue or bake in the oven for 10-12 minutes until the prawns are pink and the pineapple browned; turn once during cooking and brush with the marinade several times.